It is known amongst other things to use pyrotechnic methods, which blast the conductor or which cut the conductor by way of a mechanical system, for the rapid isolation of electric circuits.
On one hand these known circuit breakers have the disadvantage of being relatively expensive and on the other it is no longer possible to close the electric circuit again after isolation. The isolating element has to be bridged or even replaced if a false trip occurs or when the cause of the trip has been rectified.
A device for interrupting the flow of current in a cable is known from WO 97 37 873 A1. Disposed in a housing with two electrical connection terminals that are isolated from each other are two sleeves which are electrically insulated from each other, connected in each case to at least one connection terminal and are linked by a plastic sheath. A piston-like actuating element is arranged in both sleeves which makes contact with the sleeves by means of contact springs as well as joining the two sleeves electrically in a contact position and which fails to make a connection in an isolating position. Ignition of a pyrotechnic charge creates explosion gases which push the actuating element into the isolating position.
The disadvantage of the prior art is that an arc occurring at the precise moment of isolation is not safely and reliably suppressed with the result that there may be burn-out and damage to the surfaces of the actuating element and the sleeves which make reclosure or repeated actuation difficult or prevent it.
A switch is known from DE 1 260 590 which opens a charge by means of an explosion. A cylindrical housing holds a piston-like movable contact body in which an explosive charge is disposed. This charge may be ignited by separate electrical wires. The contact body is guided into a hole of the housing by a rod connected to it and on actuation of the charge is ejected out of the cylindrical part of the housing. The contact body can be pushed back by means of the rod.
The disadvantage of this prior art is that on actuation the guide may lead to wear and deflections due to the rod alone and as a result this may impede reclosure.
Therefore, it is the object of the invention to create an electric circuit breaker which is inexpensive, can easily be reclosed after actuation and which suppresses an arc that causes wear.